Treatment of materials made of or containing cellulose or cellulose derivatives



Patented Nov. 13, 1934 I j.

UNITED STATES PAT ENTj OFFICE TREATMENT OF MATERIALS MADE OF OR CONTAINING CELLULOSE OR CELLULOSE DERIVATIVES Reginald Henry Parkinson, Spondon, near Derby, England, assignor to Celanese Corporation of America, a corporation of Delaware No Drawing. Application October 15, 1930, 6Seriiigqo.488,998. InGreat Britain November 2 Claims. (Cl. 28-1) K g This invention relates to the treatment of artiinorganic materials are applied is preferably waficialfilaments, threads, yarns, ribbons, fabrics, ter, but any other suitable medium, for example films or other materials made of or containing alcohols, may be used. cellulose acetate or other cellulose esters or nat- It is remarkable that materials made of or con- 5 ural or artificial materials made of or containing taining cellulose esters or ethers should be capa- 11 1 ble of absorbing inorganic substances from a sus- The invention is more particularly concerned pension, dispersion or colloidal solution thereof, with processes for the treatment of such mateparticularly when it is considered that such inarials so as t introduce th inorganic subterials will not absorb metallic radicles from true stances. The principal object of the invention is solution, unless they are previously or simultane- 60 to introduce into artificial materials inorganic ously brought into aswollen condition. Swelling substances for the purpose of reducing or subagents may be used in the processes of the present duing, or otherwise modifying the lustre thereof, invention to accelerate the absorption. or for the purpose of weighting the same, or for The suspensions, dispersions or colloidal solu 15 the purpose of increasing the resistance of the tions for use according to the present invention to materials to heat treatments such as ironing. may be produced by any suitable process. Me- Thls latter object comes into question more parchanical disintegration in the presence of the ticularly in the case of materials made of or condispersion medium and with or without dispersataining cellulose esters or ethers. tors or protective colloids is very suitable.

For any of the above purposes it is desirable Chemical methods involving the formation of the 70 that the inorganic substance or substances introinorganic substances in the dispersion medium duced shall be white or substantially white, or as may also be employed, such formation taking light coloured as possible, since obviously it is place, if desir d or n ssa in th p nc of desirable to be able to colour such materials in p ec eelleids- Thus, for p a any desired shade. containing a metal whose oxide is desired in 001- 75 According to the present invention the mateloidal solution may be treated soas to remove rials made of or containing cellulose or cellulose a radi le 0! h lt l aving the oxide. For inesters or ethers are treated with suspensions, disstance a salt of aluminium may be dialyzed to persions or colloidal solutions of the desired inr m ve he i l r rna iv ly a sell organic substances. The substances employed containing a V i acid l'fldiele, example 80 may vary very widely and may vary according to aluminium acetate, may be boiled so as=to remove the nature of the material treated or the Object the acetate radicle and obtain the alumina in with which the inorganic substanceisintrodueed colloidal form. Again, the already formed in- White or substantially white metallic oxides are rg ni s bs ances may be peptized with the aid particularly valuable. The following are some of suitable agents, for instance acids, alkalies or 95 examples of inorganic substances which may be salts. Thus for example alumina, stannic oxide introduced, but itisto be understood that the listor titanium oxide may be Deptized with the aid ing of these examples implies no limitation of the f dilute mineral acids, for instance dilute hydroinvention thereto:-oxides of aluminium, 'titanchloric or dilute nitric acid.

40 ium, tin,,tungsten, silicon, zinc, lead, uranium, In many cases a simple treatment of the fibres cerium etc., barium carbonate, barium sulphate, or other materials in the cold with the dispersion, zinc sulphide, china clay, bentonite or other subsuspension or colloidal solution is suflicient to stantiallywhlte and insoluble silicates and kieselbring about an appreciable absorption of the inguhr. Preferably the substances introduced into organic material particularly if the electric 45 the materials are insoluble or substantially incharge of the dispersed or suspended particles is' ,5 soluble inwatersothat upon subsequent processopposite in sign to that of the material under ing of the fabrics or other materials no substantreatment. A colloidal solution of titanium oxide tial diminution of their content of inorganic maobtained by peptizing the oxide with dilute min ,7 terlal is produced. The mediuminwhich the diseral acids is thus very suitable for direct treatso persions, suspensions or colloidal solutions of the ment of cellulose acetate materials since the par- The sign of the dispersed or suspended particles may where desirable, be changed by any suitable means; for instance in the case of silica suspensions or dispersions, upon adding sodium silicate to a slight excess of dilute hydrochloric acid or other mineral acid, a negative s01 is first produced which upon addition of hydrochloric acid or other mineral acid changes first to zero and then to a positive sol. The absorption by the materials under treatment of the inorganic substance or substances, whether the latter have a charge of opposite sign to that of the materials or not, may be accelerated or'even initiated by any suitable means, for instance by heating, by electrical means or by any means which will bring about a slow coagulation or breaking of the dispersion or colloidal solution. With this latter object, the

addition of electrolytes, and especially electro- Lvtes containing di-, tri-, or polyvalent ions is particularly valuable. The coagulant should be such that coagulation in the absence of the fibre or material is relatively slow. The coagulant may be added to the colloidal solution or dispersion before introduction of the fibre or at any suitable stage subsequent thereto or alternatively the fibre or material may be separately treated with a coagulant after treatment with the colloidal solution dispersion or the like.

As indicated above, the absorptive power of the materials for the suspended, dispersed-or col-' loidally dissolved particles may be increased by previous or simultaneous treatment with a swelling agent. For instance cellulose acetate or other cellulose ester or ether may be treated with thiocyanates, acetic acid, lactic acid or. like organic acids, aromatic sulphonic acids, phenols etc., before or during the treatment with the colloidal solutions, dispersions or suspensions. In some cases in treating the material simultaneously with a swelling agent and the colloidal solution, suspension or dispersion, the swelling agent may perform the double function of swelling the fibre and at the same time eflecting a slow coagulation of the particles of the dispersion. For instance sulphonic acids have the property of swelling cellulose, esters, while at the same time they are capable of coagulating many colloidal solutions.

The temperature of the treatment may vary considerably, for example from ordinary atmos- 1 pheric temperature or lower to to or C.

or higher. In the case of cellulose acetate or like fibres, temperatures above about C. should be avoided in the case of aqueous reagents unless delustering by these aqueous reagents is required, or unless sugars, salts or other agents adapted to prevent the delustering are present. ""-"Salts for this purpose should be used with care as in many cases they may bring about too rapid a coagulation-of the suspensions or dispersions.

1 The colloidal solutions, dispersions or suspensions of the inorganic substances may be applied to the materials in any desired manner. Bath, spraying or padding treatments, 1. e. treatments by mechanical impregnation, are in most cases very suitable where it is desired to introduce the inorganic substances uniformly into the materials. For local application spraying, printing or stencilling may be employed. The colloidal solutions, dispersions or suspensions may be thickened with any suitable thickening agents, for instance those well known in the printing arts, for application by printing methods. The local application of the inorganic substances accord;

nium oxide or other lustre reducing or modifying pensions or dispersions containing 5 to 10% or even up to 50% of the dispersed substance may ing to the present invention is very valuable from the point of view of producing materials of dinerential lustre. A printing paste containing a suspension, dispersion or colloidal solution of titaagent may for example be locally applied to the I artificial material to produce a subdued lustre upon a ground of normal lustre.

w The concentration of the inorganic substances in the colloidal solutions may vary widely with the particular inorganic substance employed, with the purpose for which it is applied and with the nature of the material under treatment. For instance, colloidal solutions containing 1 to 5% or less may be used for some purposes, while susbe used in the case of requiring a weighting of the material under treatment, or in the case of increasing its resistance to heat treatment. Similarly, the actual amount of substance to be absorbed may vary considerably with the object to be achieved and also with the nature of the inorganic substances applied. In the case of reducing or subduing the lustre, proportions of inorganic substance of the order of 0.5 to 2% on the fabric or material under treatment is sumcient, thoughhigher proportions may be used,

while for increasing the heat resistance ofmaterials or for weighting, purposes, much higher 1 5 proportions of inorganic substances may. be introduced. I

As already indicated, the processes of the invention are particularly applicable to the treatment of materials made of or containing cellulose esters or ethersffor example cellulose acetate, cellulose fomate, cellulose propionate, cellulose butyrate, "immunized cotton, methyl cellulose, ethyl cellulose or benzyl cellulose, since in general it is difllcult to introduce metallic radicles into these materials without swelling and consequent temporary tendering. The invention is. however also of value in the treatment of materials made of or containing cellulose or reconstituted cellulose, e. g. cotton or materials made from viscose, cuprammonium solutions of cellulose ornitrocellulose. Mixed materials containing cellulose esters or ethers and/or cellulose including reconstituted cellulose in admixture with other fibres, for instance silk or wool, maylikewise be treated.

The following examples show the best methods known to me for carrying the invention into effect, but they are not to be considered as limiting it in any way:--

Example 1 A solution of titanium sulphate containing about 5% T10: is well cooled by adding ice and a cool 5% solution of caustic soda' run in slowly with thorough stirring until the liquor is just alkaline, the temperature being kept low, for example under 5 C., during the addition. The. precipitated hydroxide is separated from the liquor and thoroughly washed using several changes of water. It is then drained or pressed r diluted with water to give a sol containing about 5% of T102. Into the bath thus obtained cellulose acetate yarn or fabric or a-cotton or viscose yarn or fabric is entered, for example into a bath six times the weight of the goods. The goods are treated in the bath at a temperature of about 60 C. for 10 minutes to half an hour, or until the required quantity of titanium oxide has been absorbed. The goods are then lifted and washed.

Local application may be obtained by spraying the above sol on to the fabric through suitable stencils or alternatively the sol or a somewhat more concentrated sol may be thickened and applied by printing methods.

Example 2 Example 3 A solution of aluminium chloride containing about 22.5 grams A: per litre is precipitated with ammonia solution, the precipitate washed and covered with about 200 times its weight of water. The whole is then brought to the boil and a quantity of N/20 hydrochloric acid added gradually, equal to about of the volume of liquor present. The goods are then entered into the bath as described in Example 2 and treated therein until the required absorption of A120: is

obtained.

Example 4 A padding solution is made up as follows:-

400 parts bentonite 100 parts methylated spirit 50 parts 50% gum arabic solution 25 parts phenol or diethylene glycol or a mixture thereof 425 parts water A cellulose acetate fabric is above solution, the fabric then steamed for one hour at the steam pressure of 5 lbs., soaked for 20 minutes at 16 C. with a soap solution containing 2.5 grams per litre, and thefabric finally rinsed and dried.

In a similar manner a printing paste may be made up with the above constituents and a fabric, either cover pad printed therewith (i. e. printed all over), or printed locally. In this manner a fabric of uniformly low lustre is obtained or a fabric showing a pattern of low lustre on a ground of normal lustre. r

What I claim and desire to secure by Letters Patent is:--

l. Process for reducing the lustre of materials comprising cellulose acetate, comprising applying thereto a colloidal solution of aluminium oxide. 2. Process for reducing thelustre of materials comprisingcellulose acetate, comprising applying thereto a colloidal solution of aluminium oxide in presence of a swelling agent for cellulose acetate.

I REGINAID HENRY PARKINSON.

padded with the 

